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Fred,

The voltages on the secondaries of mine with the input set on the high range at 120V mains input: Pins 21 and 22- 6,3V
Pins 12 and 13- 17,4V
Pins 10 and 11- 18,6V
Pins 13 and 15- 90V
Pins 16, 17, 18, 19 and 20- 71, 59, Gnd. 59 and 71V
With slight line variations, the voltages will vary slightly. Voltages were measured with the loads applied and the 6,3V with graticule set at minimum so the a-c voltage at these pins is higher than the nominal 6,3V. This is a 6,3V winding. I would guess the other power transformers you mentioned would work. The 454 type may have a heavier winding for the heaters in the older S/N types. That is fine. The only thing that may be the difference is the current and slight physical size difference. If you can get one, it should work fine.

Mark

Any more Climate Change denial or defense posting will result in the offenders being placed on moderation.

Please keep politics etc. out of this group.

David Partridge (Group Moderator)

Sorry, I know that this is OT but I have to add my 2 cents worth here.

I live only a few miles from a beach on the Atlantic coast of Florida
and I've been visiting this area or living here and/or along the gulf coast
since the mid 1950s and the ocean levels have *not* risen here to any
noticeable degree in the last 60+ years. The Spanish began building their
fort at St Augustine in 1672 and finished in 1742 and neither it or the
ancient forts at Puerto Rico and elsewhere in the Caribbean have sunk
beneath the waves.

We know from records that the Vikings settled in Greenland before the
year 1000 and settled briefly in Newfoundland less than a century later. In
modern times (from the 1600s up until the 1960s, both of those voyages were
considered *impossible* due to the amount of sea ice along that route and
the Viking tales were disregarded until the remains of Viking settlement at
L'Anse aux Meadows, Newfoundland was discovered in the 1960s. Modern
archeology has PROVEN that the Vikings did indeed make those voyages and
settled in both places. Records and archaeology also prove that in about
1500, the Viking settlements in Greenland failed and that everyone there
died, due to worsening conditions and drastically colder weather. My point
is that we know from both historical records and from archaeological
evidence that even within the last 1000 years the north Atlantic has
experienced both much walmer and much colder climates than today. And the
world didn't end then (unless you were a Viking in Greenland!). I don't
think that there's any question that the weather has gotten warmer over the
past few years but the key question is whether it's part of a natural
climate shift or something due to man.

Considering that in the 1700s, 1600s, 1500s and earlier, everyone,
worldwide, was cooking and heating with wood or coal or peat (all of them
composed of mostly carbon) and in open fire pits or fireplaces I *seriously*
question the argument that we today are generating more CO2 and thus
causing more global warming, than we were 2, 3, 4, 5 or 6 centuries ago.

That's my perspective based on history; and not on either sides'
political arguments.

I recently got a 453A with a shorted power transformer. This short is at the primary side to earth.
As the technical manual does not specify the secondary voltages, I am looking for someone who can inform me about this.
I know the 435 and 454 have similar dc power circuitry connected to these transformers, so I wonder if a transformer from these scopes could be used. I noticed the cooling fan is connected to the secondary side as for the two other models, it is connected to the primary 115V side.
Any help would be appreciated.
Thanks in advance.

I recently got a 453A with a shorted power transformer. This short is at the primary side to earth.
As the technical manual does not specify the secondary voltages, I am looking for someone who can inform me about this.
I know the 435 and 454 have similar dc power circuitry connected to these transformers, so I wonder if a transformer from these scopes could be used. I noticed the cooling fan is connected to the secondary side as for the two other models, it is connected to the primary 115V side.
Any help would be appreciated.
Thanks in advance.

Jeff,

These would be pretty easy to make on a small home metal lathe either from steel pipe or rod, if you had one as an example. Not sure where you are located but there might be someone near you on one of these these electronic forums that probably has a second hobby (automotive, machining, etc.) using a lathe. You could end up with a near exact match. A 1/4-28 NF tap is less common than a 1/4-20 NC but are still pretty cheap (~US$3 online).

Regards

Don't forget that you could add washers under the nuts to help extend the length of threaded shaft that it keeps covered/protected.--EricSent from my Galaxy

I just received my shipment of brass threaded inserts and they are slightly shorter than the proper thumb nuts, but they are still more than adequate replacements. They do not interfere with nearby connections, and they are not nearly as ostentatious as I had feared they would be. Their length means, however, that they would not protect the ends of the hollow shaft of the binding post like the original thumb nuts do (which are slightly longer than the shaft they thread onto).

I have one more shipment of candidate parts coming. I will report back once they arrive.

-- Jeff Dutky

Thomas,

The problem with Step 3 is that when a lot of our physical infrastructure was built, prior to the 20th century, you HAD to build industrial centers near water because that was your main source of power, and the best method of transporting materials in and out. Even after the construction of railways, invention of the steam and diesel locomotives, and the harnessing of electric power, lots of industries needed an efficient means of evacuating waste heat from their factories, and a waterway was convenient and effective. Other businesses, and the people who worked in them, built near the industrial centers as well, and that is where we find ourselves today.

Addressing climate change, or addressing our vulnerability to it, is going to be unavoidably expensive. The only question is whether it will be more expensive to do nothing. Also, yes, there are considerable geopolitical difficulties in addressing climate change, including a thorny free rider problem (or maybe it's a prisoners dilemma), as well as considerable headwind from the sunk cost fallacy. Maybe some tragedy of the commons too, but it's been a long time since I took macro economics and I don't bother to recall most of it.

In the meantime, we have to address the problems when and where they happen, because we can't just snap our fingers and have everyone moved out of the way of potential harm, no matter how foreseeable that harm might be. My personal policy, in response to these kinds of disasters, is to give to established aid organizations, because money moves easier than goods, and the aid orgs have the logistics in place to efficiently transform money into action on the ground.

-- Jeff Dutky

John,

There's also the Type 1A2 that is roughly the same thing as a Type CA in terms of functionality (quite a bit wider bandwidth though). I have one that came with my Type 547 estate sale find, and I'm really not using it much. Would consider a trade for other stuff. :o)

Sean

I’m sorry but the biggest polluter in the world is a communist dictatorship. ?And they have stated unequivocally that they are not reducing output but rather they intend to increase it.Sorry again but there is zero PROOF that a few degrees of temperature change is generating floods, hurricanes, wildfires or any other catastrophes. ?You are being manipulated into accepting the new world order on the flimsiest evidence imaginable. ?We were told 15?years ago that Manhattan Island would be underwater by 2020. ?Sea level there has changed about 3 inches. ?There are a slew of possible explanations for the slight temperature changes including the most likely culprit, solar cycles. ?I know the chicken littles out there have convinced themselves, but a little independent research wouldn’t hurt.
George


Sent from AT&T Yahoo Mail for iPhone

another covid free new south welshman from mount warrigal ,wollongong.
VK2TKE

I don't know about things post-covid, but in the past, you could find:

Production overrun parts
Tools, hand and air
Industrial items, production tooling, fixtures
Surplus Tek test equipment
Test leads, probes, cables
Warranty return items (Danger! Will Robinson)
Office equipment and supplies
and ??? else.

Worth a visit if you are near PDX
JimMc

I lucked onto a 544 advertised in the Santa Fe craigslist.
The 1A1 seems good for most use cases. mine is "The third model, from ??? until the end has four-sided V/cm knobs and a FET front-end."


1A4 seems good for emulating Jim Williams with lots of traces displayed...

1A5 seems like a fine one, and can use the P6046 diff probes, (but I'd have to do the cal for P6046, which is long and detailed, and I have P6046's already matched to amps that stay together and work in any scope.)

1A7A would be nice -- same features as 7A22, more sensitive than the 1A1...

Hi All,
My thanks to Jim for the kind words. It's been a year and a half since my loss and I'm integrating that into my life. If the group can indulge me with a quick off topic comment, that would be appreciated. American Society does a very crappy job of dealing with loss, grief and the afterwards of that (whether that loss is a person, a pet, etc). Statistically, about 1/2 of you in this group will deal with great personal loss. And most of you will have a friend that great loss happens to. I can most strongly recommend the book "It's OK That You're Not OK: Meeting Grief and Loss in a Culture That Doesn't Understand" by Megan Devine. It is a book that both helps the person undergoing the loss or can help you understand how you can really help a friend going through it. Free grief classes are also available at most major medical institutions. If anyone would like to discuss further, please PM me. Thank You for the bandwidth and now back to our regularly scheduled Tek repair discussions. :) Gordon

One of my postponed projects is the construction of temperature probes
for my DM5xx meters - mostly because I have some 2 pin Lemo connectors
and a DM501A with no probe.

My research, so far, has turned up the following:

Module Probe Probe type
DM501 P6058 diode connected transistor (also P6601????)
DM501A P6601 Platinum RTD
DM502 P6439 diode connected transistor
DM504 P6602 Platinum RTD
DM511 P6602
DM5110 P6602

and Heraeus RTD sensors can be bought for a reasonable price (around
$5.00 or less) from Digikey.

Thank you both for the ideas/input on the probes. Reading between the lines I am hopefully understanding correctly the P6601 temperature probe is indeed the only option for the DM 501A, so I’m watching and waiting for the right opportunity there.

And thanks for the recommendation on the Probe Master probe set…looks perfect.

Anybody have any recommendations on a good source to check for the AA 501A parts I’m looking for?

Cory Oace

EJP thanks for that important information…to others as well.

So I’m realizing maybe some of my error in communication…I was assuming the reference “rear interface” was specific to the motherboard in the main frame. Does that terminology in this context actually refer to the backplane of the main frame? Like where the multi-pin connectors would be located on a main frame fitted with Option 2? If that’s the case I may have been confusing folks. None of my main frames have Option 2, and I don’t plan on implementing a home-grown retrofit. What I *am* interested in is a few specific interconnections mentioned earlier between main frame slots but just motherboard to motherboard using header pins and wire.

Cory Oace

To bring this back to topic, what are the sorts of things one finds at the store?? Still very curious even if I won't be able to shop there soon.Are the deals good?
? Dan

Good thought, could be that, but if the gain setting pot was intermittent, then I would expect it not to clip, since the amplifiers are designed to enable off screen deflection.

Perhaps another one?

Harvey